Abstract
The purpose of this work is to investigate the dynamic behaviors of a four-bar linkage press by considering the effect of the flexibility of the linkage and the clearance of joints. Besides, a method to find the optimal input speed was proposed.The results show that the impact force in the joints of a press with a variable speed generally is far larger than that of the press with constant speed, and the impact force of a flexible system is also far larger than that of a rigid system. Therefore, the flexibility and clearance of a real press should be considered in designing a press with a variable speed. However, if the input speed is properly designed, the impact force may be drastically reduced.